1. Field of the Invention
This invention relates to film assemblages of the type having a focal plane shutter and to shutterless cameras especially adapted for use therewith.
2. Description of the Prior Art
The prior art is relatively quiet on the subject of film assemblages having a focal plane shutter mounted therein and cameras especially adapted for use therewith. A teaching of such a film assemblage may be found in U.S. Pat. No. 462,116, granted to Ellis et al. on Oct. 27, 1891. This patent shows and describes a film assemblage comprised of a plate holder having an exposure opening therein, a plurality of film units located in alignment with the exposure opening and a shutter made from an opaque flexible sheet such as cloth. A pair of rollers within the cassette provide a means for mounting the shutter for movement between a film unit located in position for exposure and the exposure opening in the plate holder. In one position the shutter completely covers the exposure opening thereby preventing exposure of the film unit. In another position the shutter is out of alignment with the film unit thereby enabling its exposure.
The operation of the Ellis et al. device is not clear but it appears that one mounts the film assemblage to a camera and after actuating the shutter to uncover the exposure opening, removes the film assemblage from the camera. The film assemblage including the exposed film unit is then attached or mounted to a receiver and the shutter is partially actuated to uncover the exposure opening in the plate holder. The exposed film unit is then moved from the plate holder into the receiver via the uncovered exposure opening. The shutter is then partially actuated again to move it to a position wherein it completely covers the exposure opening thereby permitting the plate holder to be removed from the receiver without prematurely exposing the next film unit. Obviously, the demounting of the film assemblage from the camera after each exposure and its subsequent reattachment to the camera for the next exposure leaves much to be desired.
U.S. Pat. No. 3,550,515 granted to I. Erlichman on Dec. 29, 1970 shows a film assemblage comprising a cassette having an exposure opening in one wall thereof, and an egress opening in another wall thereof. Mounted within the cassette are a plurality of film units and an endless belt having an opening therein which is adapted to be moved into alignment with the exposure opening in the cassette prior to photographically exposing one of the film units. After each exposure of a film unit, the belt is driven to move the exposed film unit toward the exterior of the cassette via the egress opening. However, Erlichman does not teach or suggest that his endless belt could be used as a focal plane shutter.